This article is dedicated to the 90th anniversary of Sergey Andreevich Khudyakov, a prominent engineer, scientist, and mentor whose pioneering contributions shaped the development of hydrogen-based energy systems for space applications and influenced the broader field of sustainable energy. The paper provides a comprehensive account of Khudyakov’s professional trajectory, highlighting his role in the design and implementation of nuclear and hydrogen power units for spacecraft, including the development of fuel cell technologies tested under microgravity conditions and later applied to the «Buran» program.
Beyond his technical achievements, Khudyakov’s work exemplifies the integration of advanced energy concepts into civil industry, particularly in the automotive sector, where hydrogen technologies were adapted for environmentally friendly transport solutions. His scientific vision extended to the paradoxical notion that exhaust gases from thermal power plants could serve as fuel in reverse cycles, thereby challenging conventional combustion theory and opening new pathways for direct conversion of matter into electricity.
The article also emphasizes Khudyakov’s enduring role as a custodian of engineering heritage. His publications on Vasily Grabin and the masters of artillery and rocket-space engineering have become seminal works, bridging the historical continuum from artillery to astronautics and reinforcing the cultural identity of Russian engineering. His extensive teaching and lecturing activities at leading universities and research institutions, combined with active participation in international congresses on alternative energy and ecology, underscore his influence as both a scientist and educator.
By situating Khudyakov’s contributions within the broader context of energy innovation, historical continuity, and pedagogical legacy, the article demonstrates his significance as a figure who unites past achievements with future aspirations. His work not only enriches the scientific discourse on hydrogen energy and plasma-catalytic systems but also inspires new generations of researchers to pursue sustainable and transformative solutions in energy and technology.

Anaerobic digestion (AD) is a promising method for producing biogas from organic waste. A promising research area is two-stage anaerobic digestion, which can simultaneously produce hydrogen and biogas. However, the implementation of this process is limited due to its low speed and efficiency, so one strategy is to use a microbial electrolysis cell (MEC), which can improve the conversion of substrate into biogas. In this work, the effect of the applied voltage (0; 1,2 and 2,4 V) on the methane production intensity was studied in a two-stage AD model of liquid organic waste pretreated in a vortex layer apparatus (VLA). As a result, the highest biomethane production rate, 0,151 ± 0,071 L/(l · h), was obtained at a potential difference of 1,2 V on the MEC electrodes. During the experiment, the energy contribution of dark fermentation to the total volumetric energy output was 58,81-66,2%, with the lowest value of 58,81% obtained at a voltage of 1,2 V. The lowest concentration of soluble metabolic products, 0,59 g/l, was also observed in the methanogenic reactor at a potential difference of 1,2 V. In the microbial community of the dark fermentation reactor, the main hydrogen producer was the genus Thermoanaerobacterium (54,80-84,58%). In the methanogenic reactor, under the influence of a voltage of 1,2 V, the community was enriched with hydrogenotrophic methanogens of the genus Methanothermobacter and hydrogen-producing genera of Thermanaerovibrio, Cloacimonadaceae W5, Acetomicrobium, and Coprothermobacter. Thus, the use of a microbial electrolysis cell with a potential difference of 1,2 V allows increasing the energy output of a two-stage anaerobic digestion system of VLA pretreated food waste model by 33%.

The scientific article describes the features of circular heat generation and the production of clean electrical energy using renewable and non-renewable energy sources. The main concept is aimed at combining a wind power plant with combined energy and waste recycling facilities. The combined installation includes a wind generator combined with an electrical energy source. The waste treatment plant performs the function of recycling, neutralization and re-use. Waste disposal can be high-temperature, based on thermal decomposition, using plasma decomposition. The capacity of the wind power plant under consideration is 50 MW, a combined installation of 750 MW, and a waste treatment plant of 220 MW.
The study combines the use of energy resources with energy installations. This creates the possibility of producing environmentally friendly hydrogen, with increased productivity, reduced greenhouse gas emissions, savings in fuel resources, and the possibility of using and disposing of waste.
It takes into account the assessment of technical and economic indicators, the assessment of the environmental impact of combining the described installations. The dependence of the result on technical efforts is revealed according to the Pareto principle. Stochastic modeling is used to analyze systems based on statistical data. The study describes the balance between infrastructure quality and reduction of carbon dioxide emissions into the atmosphere.
The use of hydrogen in power plants ensures environmental safety, minimizes leakage risks, provides a high percentage of efficiency and reduces specific fuel consumption. However, an increase in hydrogen consumption leads to a change in the characteristics of the system and an increase in the cost of structural elements.
The reduction of carbon dioxide emissions is associated with the transition to the production of pure hydrogen. The IEA report «Zero Emissions by 2050» describes a reduction in the price of low-emission hydrogen to USD 2-9 per 1 kg by 2030. Wood Mackenzie (WoodMac), in its 2021 report, predicts the price of hydrogen to be below $1 per 1 kg by 2030. A report by Rethink Energy in 2022 stated the cost of green hydrogen by 2030 to be just over $1 per 1 kg. Argus analysts describe the prospect of a $1,3 price per 1 kg of hydrogen by 2030.
Obtaining pure hydrogen is complicated by the following factors: the high cost of hydrogen, the increased cost of building a hydrogen production plant, the logistical problem, and the storage problem. The International Energy Agency predicts a five-fold increase in demand for the use of hydrogen by 2050. Hydrogen consumption can reach up to 350 million tons per year, of which 70% will be green hydrogen.
Pure hydrogen in industry can be obtained by the following methods: steam conversion of methane, electrolysis of water and gasification of coal. Steam conversion of methane is an affordable and highly efficient technology with a hydrogen output purity of up to 98%. The disadvantage is the emission of carbon dioxide during the gas production process. The production of hydrogen through the process of water electrolysis is environmentally friendly, affordable, with a hydrogen output purity of up to 99%. One of the most common methods of producing pure hydrogen is electrolysis in industrial installations. The output is a high-quality product without impurities. The plant can produce not only hydrogen, but also other chemical compounds. Electrolysis in combination with solar or wind energy is environmentally friendly. The disadvantage of this method is the high cost and energy consumption. The method of producing hydrogen by coal gasification is the most environmentally unecological method, due to significant emissions of carbon dioxide into the atmosphere. The purity of the hydrogen at the outlet is approximately 74%.
Switching production to pure hydrogen requires additional costs, but hydrogen production using renewable energy sources is an economically viable and affordable option. The hydrogen storage procedure is more economical than transportation. Compressed hydrogen is used for storage, and underground storage facilities may be used. When transporting hydrogen, losses occur due to low density, and the problem arises of pre-cooling the vessels that are subsequently filled with gas.
The introduction of pure hydrogen production technology is in demand. The average estimated cost of producing 1 kg of pure hydrogen tends to the cost of traditional energy sources. This helps to reduce the global level of carbon dioxide pollution in the atmosphere.

This article demonstrates the relevance of the plasma method for carbon dioxide utilization. An installation for oxygen regeneration from carbon dioxide based on quasi-stationary pulsed nonequilibrium plasma is described. The percentage of oxygen in the mixture obtained using an electrochemical sensor is presented. According to the results of the work, it was found that in the installation, the maximum percentage of oxygen is achieved in the interelectrode gap of 3 mm at a pulse repetition rate of 5 kHz. The energy spent on the formation of one oxygen molecule at a flow rate of 7 l/min is 7,44 eV/mol. It was shown that in addition to oxygen, ozone is obtained in this installation, which allows an additional increase in the percentage of oxygen in the resulting mixture by decomposing ozone in hoptalum. Thus, it was shown that it is possible to create a mobile device for processing carbon dioxide obtained during human breathing into oxygen based on the discharge described in the article.

Currently, research is actively continuing on changes in the characteristics and properties of water as a result of exposure to electromagnetic waves. Studying the effects of fields on water has many practical applications in ecology, agriculture, and industry. In most cases, water is a complex heterogeneous system containing various impurities that affect the physical and chemical properties of water, even in very small quantities. The results of various experimental studies (obviously with different water samples) are not always consistent with each other. Based on a review of scientific publications, this paper analyzes the results of research related to the study of the effects of electric, magnetic and electromagnetic fields of various frequencies and strengths on the physico-chemical properties of water: specific heat, permittivity, refractive index, electrical conductivity, surface tension, wetting angle, viscosity, evaporation rate of water, pH, the absorption spectrum. An analysis of the publications showed that there are significant discrepancies in the experimental results for a number of these properties, while the results of experiments on changes in the refractive index, evaporation rate, and absorption spectrum are generally consistent with each other. If water can naturally change its properties due to electromagnetic action, then it can potentially be considered as a sensor (sensor) of radio emissions. To solve the problem of inconsistency of experimental results, recommendations are given for their presentation.

The effect of the Ni/Mg molar ratio on the physicochemical and catalytic properties of mixed Ni-Mg-Al-O oxides obtained by heat treatment of layered double hydroxides has been studied. An increase in the nickel content and the catalyst reduction temperature leads to an increase in the degree of nickel reduction and a decrease in its dispersion due to sintering processes occurring at high temperatures. As the Ni/Mg ratio increases, the stearic acid conversion and the yield of C15-C18 hydrocarbons increase. The complete transformation of stearic acid to heptadecane as the main product is provided by the catalyst with the molar ratio Ni/Mg of 3 at 270 ° C and 4 MPa for 5 hours.

Reducing greenhouse-gas emissions in the production of heat and electricity is one of the key avenues of sustainable development. Transitioning from hydrocarbon fuels to hydrogen will virtually eliminate carbon-dioxide formation in the combustion chambers of gas-turbine units while simultaneously increasing the water-vapor content in the combustion products, which makes recovery of the low-grade heat of water vapor from the flue-gas stream in condensing heat-recovery boilers promising. This study presents the results of a comprehensive analysis of combined-cycle power blocks operating on hydrogen and methane–hydrogen mixtures, with additional recovery of the low-grade heat of wet combustion products in Organic Rankine Cycles. The energy-efficiency level of the units is determined, a RANS-based methodology for modeling heat transfer in condensing heat-recovery steam generators is refined, and the overall dimensions of the heat-recovery system are assessed.